Analytical Methods
·
2014
·Vol. 6
·期 7
·2294-2298
·
IF 1.938
Zonghao Li,Jiaxi Chen,Mousheng Liu,Yaling Yang
A supramolecular solvent made up of reverse micelles of nonanoic acid, dispersed in a continuous phase of tetrahydrofuran (THF) and water, is proposed for the simple, rapid and efficient microextraction of copper (Cu) and lead (Pb) in water samples prior to flame atomic absorption spectrometry determination. A new Schiff base was synthesized and used as the chelating agent in this study. Some important extraction parameters such as the pH, Schiff base concentration, the composition and volume of the supramolecular solvent and vortex time are evaluated, obtaining the most favorable results. Under the optimized conditions, the calibration curves were linear in the range of 10–800 μg L−1 for Cu and 10–500 μg L−1 for Pb, respectively. The limits of detection (LOD) were 0.29 μg L−1 and 0.45 μg L−1, with the enrichment factors of 27 and 22 for Cu and Pb, respectively. Recoveries of Cu and Pb spiked in water samples were in the range of 91.2–102.1%. The results show that the proposed method is suitable for the determination of Cu and Pb in water samples.
研究领域:
分析化学
·
环境化学
·
分离科学
·
重金属检测
·
样品前处理
✓ 已验证
DOI
高影响因子
Analytical Methods
·
2017
·Vol. 9
·期 47
·6669-6674
·
IF 1.9
Hui Huang,Jiao Li,Mengxian Liu,Zizhun Wang,Bingdi Wang,Meini Li,Yongxin Li
A novel multifunctional semiconducting polymer dot (Pdots)/pyrogallic acid (PA) system was successfully established for fluorescence sensing of urea, urease, and pesticides. The Pdots/PA system was pH controllable, emitting strong fluorescence at pH 6.0. However, in an alkaline environment, PA transformed into its quinone structure, which is an efficient fluorescence quencher, resulting in fluorescence quenching of the Pdots/PA system. Furthermore, urea was hydrolyzed in the presence of urease, releasing hydroxyl groups that transformed PA into its quinone structure, resulting in fluorescence quenching of the Pdots/PA system. Therefore, a sensitive detection method for urea and urease was developed. The limits of detection for urea and urease were 0.02 mM and 0.08 U L−1, respectively. Pesticides, such as dimethoate, were able to inhibit the urease activity, resulting in recovery of the fluorescence intensity of the Pdots/PA system. Therefore, the fluorescence turn-on detection of pesticides could be also achieved. A satisfactory result was obtained when using the system to detect pesticides in fruit and vegetable samples.
研究领域:
分析化学
·
生物传感器
·
环境监测
·
食品安全
·
分子探针
·
酶学
✓ 已验证
DOI
高影响因子
Analytical Methods
·
2017
·Vol. 9
·期 36
·5274-5280
·
IF 1.9
Yurong Tang,Shuguang Yan,Hang Ye,Fenglan Zheng,Liu Feng,Feng Liu,Xulong Li
The design of quantum dots as a new sensing platform is very important for developing high-sensitivity fluorescent sensors. However, achieving a new strategy is still a great challenge. Here, a new strategy for fabricating water-dispersible thiol malic acid modified ZnSe quantum dots (TMA-ZnSe QDs) is presented in aqueous solution. The characteristics of the modified TMA-ZnSe QDs and the interactions between TMA-ZnSe QDs, Al3+ and rutin were investigated by atomic force microscopy, energy dispersive X-ray spectroscopy, fluorescence spectrometry, resonance Rayleigh scattering, UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy. A new high-sensitivity fluorescent sensor based on tuning the aggregation/disaggregation behavior of TMA-ZnSe QDs by structure-switching for the detection of rutin was developed. The results confirmed that the detection sensitivity was greatly improved by the aggregation of TMA-ZnSe QDs with Al3+ because rutin effectively quenched the FL of TMA-ZnSe QDs–Al3+via the photoinduced electron transfer process. Under optimum conditions, the decrease in the FL intensity was linear to the rutin concentration from 0.02 μg mL−1 to 9 μg mL−1 and the detection limit for rutin was 0.02 μg mL−1. The proposed method offered a new possibility for rutin detection in real samples owing to its low cost, simplicity, high sensitivity and good stability. The present work provides a new strategy for improving sensitivity by tuning the aggregation/disaggregation behavior of TMA-ZnSe QDs.
研究领域:
分析化学
·
纳米生物技术
·
分子诊断
·
药物分析
·
荧光传感
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Qi Li,Pengcheng Wu,Yufan Huang,Peng Chen,Keliang Wu,Jianning Wu,Yan Luo,Lele Wang,Shengchao Yang,Zhiyong Liu,Xuhong Guo
Traditional surface-to-surface contact heterojunctions suffer from poor stability and low electron-hole separation efficiency, which has become a crucial limiting the further improvement of photocatalytic property. Therefore, improving the combination of heterogeneous materials will become a new attempt. In this work, a novel lattice embedded ZnO@TiO 2 (B) nanoflowers was prepared by combining electrodeposition method combined with hot solvent method. The hetero interface of the ZnO@TiO 2 (B) nanoflowers is distributed in the phase of TiO 2 (B), which drives high-efficiency charge separation. The sample Zn:Ti 1:4 has the highest photocatalytic property, and the H 2 generation efficiency under the full spectrum is 1.695 mmol g −1 h −1 , which is 3.5 times that of TiO 2 (B). After 36 h cycle stability test, its stability is as high as 90%. According to results, the possible mechanism of ZnO@TiO 2 (B) photocatalytic hydrogen production is proposed. These findings may provide new strategies for the preparation of high-efficiency heterojunction photocatalysts with special structures.
研究领域:
材料科学
·
光催化
·
纳米材料
·
能源化学
·
半导体物理
·
环境功能材料
✓ 已验证
DOI
高影响因子
Polymer Chemistry
·
2016
·Vol. 7
·期 6
·1330-1336
·
IF 5.687
Fei Chen,Jiangna Guo,Dan Xu,Feng Yan
Thermo- and pH-responsive poly(ionic liquid) (PIL) membranes were synthesized via photo-crosslinking of imidazolium type IL monomers with acrylic acid (AA), N-isopropylacrylamide (NIPAM), and acrylonitrile (AN). The transmittance of the prepared PIL membranes was determined by the concentration of AA units and the hydrophobicity of PIL counter anions, and could be altered in response to temperature and (or) pH. The shape deformation of the PIL membranes can be reversibly tuned by changing the pH value of aqueous solutions or gas atmospheres (NH3/HCl). The dual-responsive PIL membranes prepared in this work can act as a soft actuator, and would have potential applications in advanced sensors and functional materials for inscription of information.
研究领域:
高分子化学
·
智能材料
·
响应性聚合物
·
生物医用材料
·
功能材料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2012
·Vol. 3
·期 7
·2227-2233
·
IF 0
Zhengping Dong,Xin Tian,Yuanzhe Chen,Jingran Hou,Jiantai Ma
Rhodamine group modified SBA-15 nanocomposite (R3-SBA-15) is investigated as a highly selective Hg2+ sensor. The colorless sensor converts to red color in the presence of Hg2+ with the fluorescent detection limit for Hg2+ in MeCN–H2O solution (9 : 1 v/v) being 15 ppb levels and exhibits excellent Hg2+-specific luminescence enhancement over various competitive cations, including alkali and earth, the first-row transition metals and heavy metals. According to the definition of Boolean Logic, using Hg2+ and S2− as inputs, the fluorescence intensity signal changes of R3-SBA-15 as outputs, R3-SBA-15 can act as an INHIBIT logic gate. All the results suggest that R3-SBA-15 was possible for real-time quantitative detection of Hg2+ and the convenience for potential application as a logic gate operated at the nanoscale level.
研究领域:
分析化学
·
纳米科学与技术
·
环境监测
·
生物传感
·
分子探针
✓ 已验证
DOI
WATER SCIENCE AND TECHNOLOGY
·
2013
·Vol. 69
·期 3
·580-586
·
IF 1.102
Meng Lifen,Cheng Jiaxi,Yang Yaling
A simple and practical extraction method of supramolecular solvents (SUPRAS) was developed for separation and enrichment of trace amounts of palladium (Pd) and silver (Ag) in water samples prior to flame atomic absorption spectrometry (FAAS) analysis. The SUPRAS selected was made up of an aqueous solution containing tetrahydrofuran and nonanoic acid. Pd and Ag reacted with diethyldithiocarbamate to form hydrophobic chelates, which were extracted into the vesicles of SUPRAS. Different parameters such as the concentration of chelating agent, sample pH, supramolecular solvent and the effect of foreign ions were studied. Under the optimal conditions, the linear ranges of Pd and Ag were from 10 to 1,000 μg/L. The relative recoveries of Pd and Ag in tap and river water samples at the spiking level of 10 ug/mL ranged from 90.8 to 116%. The relative standard deviations were 3.6–4.0% ( n = 9), the limits of detection were 2.8 and 1.9 μg/L and the enrichment factors were 36 and 18 for Pd and Ag, respectively. The quantification limits were 3.2 and 2.4 μg/L. The method was successfully applied to the determination of Pd and Ag in water samples.
研究领域:
分析化学
·
环境化学
·
分离科学
·
痕量元素分析
·
样品前处理
✓ 已验证
DOI
高影响因子
WATER SCIENCE AND TECHNOLOGY
·
2019
·Vol. 80
·期 9
·1673-1682
·
IF 1.624
Li Xiaoqiang,Zhang Jialin,Pang Zengyuan,Zhu Yanan,Chen Xin,Sun Qian,Li Yonggui
In this work, titanium dioxide (TiO 2 ) was modified with reduced graphene oxide (rGO), and then coated on filter paper to prepare the rGT/FP photoelectrode for the photoelectrocatalytic (PEC) decolorization of methylene blue (MB). The physicochemical properties of the rGT/FP photoelectrode were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis and UV-Vis diffuse reflectance spectroscopy (DRS). The decolorization results demonstrated that the photocatalytic (PC) and electrocatalytic (EC) efficiency of the photoelectrode could be significantly improved by the modification of rGO. The improvement of PC and EC efficiency might attribute to the existence of rGO, which could extend the light-harvesting efficiency, promote the photocurrent response value and suppress the charge recombination. Furthermore, the PEC decolorization of MB using the rGT/FP photoelectrode presented higher efficiency than the sum of PC and EC decolorization, indicating the synergistic effect between the photo and electrical energy.
研究领域:
环境化学
·
材料科学
·
催化化学
·
光催化
·
电化学
·
水处理技术
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2018
·
IF 4.358
Zhaocheng Zhang,Dongyang He,Haiyang Liu,Miao Ren,Yanan Zhang,Jiao Qu,Nan Lu,Jiunian Guan,Xing Yuan
Black phosphorus (BP), a superior two-dimensional (2D) semiconductor, has attracted much attention due to its unique properties. The graphene (GR)-BP hybrid was synthesized through one pot chemical vapor transport (CVT) approach. The characterization results indicated that P atom was successfully incorporated into GR by the formation of P-C bond. Remarkably, the newly-synthesized GR-BP represented high photocatalytic activity towards 2-chlorophenol (2-CP) degradation, due to the high efficiency of charge separation and transformation caused by the direct band gap of BP and carrier mobility of GR. The removal efficiency for 2-CP reached up to 87.08% within visible light irradiation for 180 min ( λ > 420 nm). The degradation rate of GR-BP hybrid for 2-CP was approximately 7.29-fold than that of BP within 30 min. In addition, the little increasing of the peak for P-O bond in GR-BP hybrid was observed after being exposed in air for 15 days, meant that the stability of BP was significantly enhanced. It was caused by the decreasing of the oxidation sites in BP due to the formation of P-C bond in hybrid. In brief, our synthetic method for GR-BP not only provides a novel route for the improvement of the stability of BP, but also constitutes an insight into the promising practical application of BP in the photocatalysis field.
研究领域:
材料科学
·
纳米科技
·
光催化
·
半导体材料
·
环境化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2020
·Vol. 44
·期 11
·8555-8566
·
IF 3.741
Li Yang,Yanping Yuan,Nan Zhang,Yanfang Dong,Yafen Sun,Wenhui Ji
Summary To make better use of solar energy, lauric acid/expanded graphite (LA/EG) composite phase change materials (PCMs) were synthesized to collect and store solar energy as latent heat thermal energy. The results of thermal characteristics show that when the mass fraction of EG is 5%, 10%, and 15%, the latent heat of LA/EG is 164.5, 156.9, and 148.0 J/g, and the thermal conductivity is 2.73, 7.98, and 10.54 W/(m·K). Leakage test shows that LA/EG PCMs with EG mass fraction of 10% and 15% are form stable after phase change. One thousand thermal cycles prove good thermal reliability of LA/EG. TG analysis indicates LA/EG PCMs have good thermal stability within operating temperature range. The Ultraviolet-visible spectra reveal that the absorbance of LA/EG composite PCMs would increase as the mass fraction of EG increases. Photothermal conversion experiment results indicate that the photothermal conversion efficiency of LA/EG composite PCMs increases as the mass fraction of EG increases, and the efficiency can reach 95% when the mass fraction of EG is 15%. Moreover, it was also found that the process of photothermal conversion can be accelerated with stronger illumination intensity or smaller heat transfer size. All the results show that the prepared LA/EG PCMs can convert solar energy into thermal energy and store it in the form of latent heat at the same time, which indicates it has promising prospect in the application of solar energy conversion and storage.
研究领域:
材料科学
·
能源化学
·
热能工程
·
功能材料
·
可再生能源
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Xingchao Zhang,Ruoyu Zhang,Siying Niu,Jiming Zheng,Chongfeng Guo
The MoS 2 /g-C 3 N 4 heterojunction composite (marked as MoS 2 /g-C 3 N 4 -H) was successfully prepared via calcining the melamine coated MoS 2 nano-sphere, where the thin g-C 3 N 4 nano-sheets were tightly grown on the surface of MoS 2 nano-sphere to form MoS 2 inlaying in g-C 3 N 4 heterostructure. The detailed charge transfer mechanism was discussed by combining theoretical calculation and experiments, in which the intrinsic cause of photo-generated charge separation and transfer was determined as the directional built-in electric field driven by different Fermi levels of MoS 2 and g-C 3 N 4 . Comparatively, the enhanced photo-catalytic performance and stability of the sample were assessed by degrading the Rhodamine (RhB) and reducing the Dichromate (Cr 6+ ) solutions under the irradiation of the simulated sunlight, which could be attributed to the widened spectral absorption range and improved electron-hole separation rate. Based on above results, the photo-catalytic mechanism involving redox reactions was also clearly proposed.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY
·
2016
·
IF 1.914
Kun Shan,Ping Zhou,Yunsheng Zuo,Renke Kang,Dongming Guo
Electrogenerated chemical polishing (EGCP) had been proved effective in improving both the smoothness and the flatness of copper surface in our previous work. In this paper the polishing ability, defined as the ratio between the material removal rate at the peak and at the valley of a rough surface, is studied theoretically and experimentally. In a mathematical model, the effects of the special wavelength L , the peak-to-valley height h of the workpiece surface profile and the working distance d between working electrode and workpiece surface on the polishing ability are studied. The results show that the polishing ability decreases with increasing the working distance and finally approaches the value ( d + h )/ d , if L is much larger than d . However, the effect of the working distance on polishing ability is negligible, if L is close to or less than d . The polishing ability also decreases with h decreasing. Based on the above analysis, an analytical expression of the polishing ability of EGCP is given. For validating the theoretical analysis, a copper surface is polished by EGCP and the change of the surface profile is measured and analyzed using the analytical expression. The measured polishing ability agrees well with the simulation results.
研究领域:
材料科学
·
表面工程
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）